1. Field of the Invention
The present invention relates to a photosensitive resin composition containing a Fullerton as photosensitive crosslinking agent. More precisely, it relates to a photosensitive resin composition which is photo-curable even with light of visible range. The photosensitive resin composition of the present invention is useful as, for example, a photo resist used in the fields of semiconductor devices, liquid crystal elements and the like.
2. Related Art
As negative type resists for the production of semiconductors, liquid crystal display elements and the like, for example, mixtures of a photo-activated radical generating agent such as stilbazole-denatured polyvinyl alcohol and benzophenone and a multivalent acrylate are used. Upon use of this type of resists, they are cured by irradiation by a light source of g-ray (436 nm), i-ray (366 nm) or the like.
Resists utilizing fullerenes have also been known. For example, Japanese Patent Unexamined Publication No. Hei 6-167812 (JP-A-167812/84) discloses a photosensitive composition comprising a Fullerton and a photosensitive material. Japanese Patent Unexamined Publication No. Hei 6-19136 (JP-A-19136/84) discloses a photosensitive material obtained by introducing photosensitive groups into a fullerene. Japanese Patent Unexamined Publication No. Hei 7-134413 (JP-A-134413/85) discloses a process for making devices utilizing a resist material containing a fullerene. These compositions or process are basically for producing films by linking fullerenes one another and require a large amount of fullerenes. However, fullerenes are presently expensive materials and, therefore, the production of photoresists using these compositions is not practical.
Japanese Patent Unexamined Publication No. Hei 7-62105 (JP-A-62105/85) discloses a fullerene-containing silicon polymer, and describes that the polymer is a photosensitive resin containing fullerenes in its backbone and its photosensitivity is obtained by the silicon atoms contained in the backbone.
In order to cure these resists, irradiation of ultra-violet ray or radioactive ray of shorter wavelength is needed. While it becomes easier to form finer patterns by using a radioactive ray of shorter wavelength, it requires irradiation of a larger quantity of radioactive ray when a radioactive ray absorber such as carbon black is contained in the resists. On the other hand, if not so fine patterns are needed and the resist can be cured with light of visible range, it is not necessary to use the hazardous radioactive ray of short wavelength.
Therefore, an object of the present invention is to provide a novel photosensitive resin composition utilizing a relatively small amount of Fullerton and curable with light of visible range.
Another object of the present invention is to provide a method for forming negative type picture elements utilizing the photosensitive resin composition and method for producing devices.